Hydraulic hand tool having opposed work-engaging jaws



J. A. BOURNE Aug. 9, 1960 HYDRAULIC HAND TOOL HAVING OPPOSEDWORK-ENGAGING JAWS 2 Sheets-Sheet 1 Filed Dec.

INVENTOR. JOHN 4. same/v5 Aug. 9, 1960 J. A. BOURNE 2,948,174

HYDRAULIC HAND TOOL HAVING OPPOSED WORK-ENGAGING JAWS Filed Dec. 12,1958 V 2 Sheets-Sheet 2 W -w .65 a 7 f 94 f INVENTOR. Jaw/y 4. 5002445,79 'BY' v ,7 TTOEIVE gs.

Uni ed State ate t D ice HYDRAULIC HAND TOOL HAVING OPPOSEDWORK-ENGAGING JAWS John A. Bourne, .0. Box 88, Hamilton, Bermuda FiledDec. 12, 1958, Ser. No. 780,013

- 9 Claims. (Cl. 81-129) This invention relates generally to hand tools,and more particularly has reference to a hydraulically operated toolfalling into the category of work-gripping mechanisms. In this generalcategory would fall wrenches of the slidable jaw type, pliers, tongs,clamps, various tools of the type having one or both jaws pivotallymounted, etc. The invention, hereinafter, will be described withparticular reference to its adaptability for incorporation in a wrenchof the type having a slidable jaw movable toward and away from a fixedjaw. Such a wrench, for example, might be a Stillson wrench, this beingatype of tool in which a particularly 'strong clamping force must beexerted upon the work by the opposedfljaws. Nevertheless, it will beapparent that this is merely one example of the invention, and the principles thereof could obviously be adapted for any of various other toolconstructions, such as those touched upon above.

One important object is to provide an improved hydraulically operatedhand tool, which will be characterized by its comparatively simpleconstruction, considering the advantages tobe obtained from the usethereof.

Another object is to provide a too-l as stated which will beparticularly compact, and light, thus 'to permit it to be grasped by aworker with a minimum of difliculty,'easily maneuvered,:moved into andout of cramped quarters, and otherwise handled with maximum ease. V

Still another object of importance is to overcome a difliculty which hasbeen noted in connection with hydraulic tools of the charatcer stated,through'the' provision of a cylinder which is freely rotatable relativeto the body of the tool. By reason of'this arrangement, it is proposedto permit the cylinder to gravitate to a lower: most position, duringthe ordinary manipulation of the tool when it is in use, whereby tolocate the fluid contained in the reservoir of the cylinder in an areaof the reservoir from which it can be pumped.

Still another object is to provide, in combination with the freelyrotatable cylinder, a weighted, flexible tube within the cylinder, theweighted portion of which constitutes the inlet of the tube and isautomatically movable into the lower portion of the cylinder, as thecylinder rotates by gravitational action. In this way, it is proposed toinsure to the maximum, by a coaction between the freely rotatingcylinder and the movements of the weighted tube, that fluid in thereservoir will at all times be available for passage through the tubeinto the hereof the pump assembly of the device.

Another object is to provide a generally improved pumping mechanism,wherein the means carrying the cylinder will not only be journalledin'the body of the device to provide the above mentioned rotatablemounting of the cylinder, but also will serve to provide the bore of thepump mechanism.

- Yet another object is to provide a device of the class describedwherein the means mentioned immediately Patented Aug. 9, 1960 above willsupport 'for reciprocating movement a pump rod, as well as ahydraulically advanced ram.

Still another object is to provide, in combination with the ram, 21motion-translating means extending between the ram and the movablejaw,such that straight line movement of the ram in a particulardirectionwill be translated into straight line movement of the movablejaw in a path angular to that along which the ram is moved.

'Another object is toso design the motion-translating means that extendsbetween the ram and movable jaw as to produce a mechanical advantage atthe location of the movable jaw, designed to provide a particularlygreat clamping force against the work-piece.

Still another object of importance is to provide means extending betweenthe'fix'ed and movable jaws of the device, so designed as to normallybias the movable jaw away from the fixed jaw, with said means not onlyserving to tend to shift the movable jaw toward awork-disengagingxposltion, but also serving to return the ram to anormally retracted position within its associated bore of thecylinder-supporting rod of the device.

-A further object is to provide a tool as stated which will be' rugged,substantially trouble-free in operation, comparatively inexpensive, andpossessed of considerable strength in' relation to its lightness.

Other objects will appear from the following description, the claimsappendedj theretopand from the annexed drawings, in which like referencecharacters designate like parts throughout the several views, andwherein:

Figure '1 is'a' perspective view of a hydraulic toolaccording to thepresent invention; 7

Figure;2 is a slightly enlarged longitudinal sectional View through thetook-taken substantially on line 2--2 of Figure I; I

' Figure 3 is a transverse sectional view through the head of the tool,on the same scale as Figure 2, taken substantially on line 3-3 of Figure2;

. Figure 4 is a still further enlarged transverse sectional view throughthe tool, substantially on line 4-4 of Figure 2, showing the handleand'the jaw-operating mechanism of the device;

. Figure 5 is a transverse sectional view through the base portion ofthe head, on the same scale as Figure 4, taken substantially on line 5-5of Figure 2; a

Figure 6 is a still further enlarged, detail longitudinal sectional view'through the pump-structure, taken substantially (an line ti -6 ofFigure '2; and

Figure 7' is a-transverse sectional view, on substantially the samescale as-Figure 6, taken on line 7-7 of Figure 6, sh'owingthe means forreturning fluid from the pump bore to the reservoir. 7 1 a Referring tothe drawings in detail, generally designated at 10 is an elongated,straight, substantially flat handle in the form of an open center,rectangular frame having over themajor part of its area a longitudinalopening 12'; Opening 12 opens upon opposite .fiacesof the-handle asclearly seen in Figure l, and defines longitudinal walls 14 upon thehandle, integralat their opposite ends with an outer end wall 16 aridaninnerendwall 15 of the handle. .v-Generally designated at. 20 is -ahead, including a hollow, generally flat base part-2 2 which in effectconstitutes an extension of the inner-endportion of the handle. Basepart 22 isprovided, in oneface thereof, with a recess '24; Thus, theinnerend wall 18. of the handle comprises a transverse partition,separating the recess 24 from the longitudinal opening12 of the handle.

A cover plate 26 normallycloses the recess (sceFig-ure 5), being securedto the opposite sidesof the head through themedium of screws '28. v V

Recess 24 is provided with an extension 30 (see-Fig,- ures 1 and 2),said extension extending forwardly into the head and being normallycovered by an extension portion 32 of the cover plate 26. The extensionportion is progressively reduced in width in a direction toward the headend of the tool, as shown in Figure 1.

Designated at34 is a cross member of the head, said cross memberextending across the head end of the recess extension 30. The crossmember 34 is spaced from the bottom wall 35 of the head, thus definingbetween said bottom wall 35 and cross member 34 an elongated guide slot36 opening into the recess extension 30 (see Figure 2).

Projecting forwardly from the cross member is a nose-like formationcomprising a fixed jaw 38.

The handle and head, having the construction described above, areintegrally connected in the illustrated embodiments, so that togetherthey constitute a body 40 of the device, said body supporting theseveral movable components to be described hereinafter.

Designated at 42 is a movable jaw which is in confronting relation tothe fixed jaw 38, thus to permit a work-piece, not shown, to be securelygripped therebetween responsive to advancing of the movable jaw towardthe fixed jaw. The movable jaw is slidable in a straight line toward andaway from the fixed jaw, in the guide slot 36, through the provision ofa guide tongue 44 integrally formed upon the inner end of the movablejaw. The guide tongue of generally rectangular configuration (seeFigures 2 and 3). However, it has a cylindrically shaped enlargement orguide rib 46, freely slidable in a complementarily shaped portion of theguide slot 36. In this way, the movable jaw .is maintained in properposition relative to the work and fixed jaw, during its advancementtoward the fixed jaw and its retraction out of engagement with awork-piece.

Designated at 48 is a support stem for the movable jaw, on which themovable jaw is guided during the above mentioned movement thereof. Thestem 48 comprises an elongated screw having a head 50 at one end, and areduced, threaded axial extension 51 at its other end. The extension 51engages in a complementarily threaded recess provided in the fixed jaw38.

Circumposed about the stem 48 is a compression spring 52, abutting atits opposite ends against the movable and fixed jaws, so as to normallybias the movable jaw away from the fixed jaw.

Generally designated at 54 is an operating mechanism for the movablejaw. This includes a hydraulic assembly, in which is incorporated ahydraulic cylinder 56. Cylinder 56 is of elongated form, extendinglongitudinally within the opening 12.

The cylinder 56 contains a quantity of hydraulic fluid, not shown, andis so mounted as to be bodily rotatable to any of a plurality ofpositions in respect to the body of the device. Thus, as shown in Figure4, the cylinder can move to any of the four positions shown in thisfigure of the drawings, one of these positions being shown in full linesand the remaining positions being shown in dotted lines. Of course, thecylinder is movable to any of a large number of other positions, sinceit is freely swingable through 360 degrees about the axis defined by anelongated support rod 58 rigid with the cylinder.

The support rod 58 extends longitudinally and centrally of the handle,within the opening, and at its opposite ends is journalled in ballbearings 60 carried by the end walls 16, 18 of the handle.

As will be noted, the support rod 58 is eccentrically disposed inrespect to the cylinder (see Figure 4), said rod extending in parallel,spaced relation to the longitudinal median line of the cylinder. -Thiscauses the cylinder to be rotatable about an axis eccentric to thecircular cross sectional configuration of the cylinder.

Designated at 62 is an angular handle, of L-shape having a long legextending in fairly close proximity to one of the side walls -14. Thehandle 62, at one end, is pivoted upon cars 64 projecting outwardly fromthe end wall 16. Thus, one grasping the handle can shift the pump handle62 toward and away from the main handle 10 of the device.

Designated at 66 is an elongated pump rod, having an outer end bearingagainst a projection 67 provided upon the pump handle. The projectionmerely contacts the pump rod 66, so that responsive to pivotal movementof the pump handle, the rod 66 will be shifted in a straight line withinthe tubular support rod 58.

Referring to Figure 6, at its inner end the pump rod 66 is provided withgaskets 68. V I

The tubular formation of the support rod defines a longitudinal bore 69therein, in which the pump rod is reciprocable. A compression spring 70bears against one end of the pump rod, within the bore 69, bearing -atits other end against a check valve housing 72 threadedly engaged inbore 69. A spring loaded check ball 74 within housing 72 normally seatsin position preventing flow through a passage 76 of the housing.

Designated at 78 is a laterally projecting check valve housing rigidwith the supporting rod 58, and communieating with 'a fluid reservoir 79defined by the cylinder exteriorly of the support rod. The housing 78has a tubular projection to which is connected one end of an elongatedflexible tube. Within the housing 78 there is provided a spring loadedcheck ball 80 controlling flow from the reservoir into the bore 69.

The flexible tube has been designated 82. Housing 78 is disposedmedially between the opposite ends of the cylinder, with tube 82 beingof a length such as to extend from housing 78 into close proximity toeither end of the cylinder, depending upon the direction in which thetube happens to extend during a particular use of the tool.

Tube 82, at its distal end, is provided with a tubular weight 84,through which fluid F flows from the reservoir into the tube. The weightcauses the distal end of the tube to seek the lowermost portion of thecylinder, regardless of the position of the tool. This assures that atall times, the weighted end of the tube will be immersed in fiuid F, toassure against interruption of flow of fluid into the tube, during thepumping action.

Referring to Figures 2 and 7, a screw 86 is threadedly engaged in anopening 87 formed in the wall of the cylinder and communicating with thebore 69. Screw 86, Whenthreaded inwardly to its maximum extent,compresses a sealing gasket 88 to prevent leakage about the shank of thescrew. Even when the screw has been backed out of the opening to apredetermined extent from its normal, Figure 7 position, gasket 88remains suifioiently compressed to prevent leakage about the screwshank.

The screw, at its inner end, has a conical tip 89, which normally seatsin an aperture 90 communicating between bore 69 and reservoir 79. Thus,when the screw is in closed position, flow through the aperture isprevented. This is the screw position during a pumping action intendedto pump fluid from the reservoir into the bore. When the screw is backedoff in the manner described above, flow is permitted through aperture 90from bore 69 to reservoir 79, to return fluid to the reservoir after thepumping action, at a time when it is desired to eliminate fluid pressurewithin the bore and, consequently, eliminate the clamping action of thejaws upon the workpiece. In these circumstances, as previously noted,the backing oif of the screw still leaves gasket 88 sulficientlycompressed to prevent leakage. However, any fluid that was previouslypumped into the bore 69 about the screw is now free to flow back intothe reservoir 79.

Designated at 92 is a ram, provided (Figure 6) with gaskets 94 at itsinner end. Ram 92 is slidably reciprocable within support rod 58, andwhen fluid is pumped into the bore 69 through passage 76, it causes theram to be extended under fluid pressure in a direction toward the headof the tool.

At its head-adjacent end, the ram is provided with a laterallyprojecting pusher foot 96. Slidably contacting the pusher foot is therounded distal end of the longer leg 97 of a bell crank 98 ofacute-angular shape. The bell crank also'has a shorter leg 99, providing'a mechanicaladvantage at the locationof the movable jaw. The shorterleg has a rounded distal end loosely engaging in an aperture 100 formedin guide tongue 44 and communicating with a bore 101 of the guidetongue.

The bell crank is' pivoted, at the juncture of its legs, on a pivot pin102 mounted within the recess extension 30.

By reason or this arrangement, when the pump handle is operated, fluidwill be pumped from the reservoir into the bore, in back of the ram.This results from the fact that each time the pump handle is swungtoward the body 40 of the device, from its normal, outwardly movedposition, shown in Figure 2, the pump rod 66 moves upwardly in Figure 2against the restraint of spring 70. Then, spring 70 tending to expandshifts the pump rod downwardly in Figure 2, back to, its initialposition. This creates a suction within'the bore 69, downstream fromvalve housing 72 (Figure 6). On the next pressure stroke of the pumphandle and pump rod, fluid will have already entered the bore 69downstream from the valve housing 72, by reason of the suction actiondescribed immediately above, and will now be forced through the valvehousing 72, with check valve ball 74 unseating at this stage of theoperation. Said fluid will, as the pumping action continues, shift theram 92 upwardly in Figure 2 to cause the movable jaw 42 to be movedtoward fixed jaw 38 into a workgripping position. The operation of thecheck balls 74, 80, will be readily understood, it being apparent thatcheck ball 80 will permit flow only from the reservoir into the pumpchamber, that is, into the bore 69 downstream from valve housing 72,during the pumping action. Check ball 74 permits flow only from the pumpchamber, which has been designated at 104 in Figure 6, into the pressurechamber 106, said chambers being parts of the bore 69. Shbsequently, atsuch time as the work is to be released, one merely backs ofl screw 86slightly from its normal position. Fluid previously pumped into thepressure chamber 106 will now be free to flow back into the reservoir,awaiting the next use of the device. The screw is then returned to itsFigure 7 position, before the device is used again.

-A very important feature resides in the adaptability of the entirecylinder 56 to freely rotate bodily about an axis defined by the tubularsupport rod 58. The cylinder thus seeks its lowermost position, bygravitational action, during the ordinary manipulation of the wrench.This causes the fluid to be disposed in an area of the cylinder, at alltimes, such as to locate the fluid properly for pumping of the same intothe pump chamber.

There is a coaction between this free rotational movement of thecylinder, about an axis eccentric thereto, and the use of a flexible,weighted tube 82. As previously noted, the cylinder tends to rotatebodily about its axis defined by support rod 58, to a lowermostposition. At the same time, the tube 82 tends to move toward thelowermost part of the cylinder, being of a highly flexible material andbeing properly weighted, as at 84. The inlet end of the tube is thusalways disposed in the fluid, by reason of the coactive relationship ofthe rotating cylinder and the flexible, weighted tube.

It may be desirable to provide communication between the interior of thereservoir and atmosphere, in order to insure positively against theformation of a partial vacuum within the reservoir during the pumping offluid out of the reservoir into the pump chamber.

Any of various means might be employed for this purpose, and in Figure7, by way of example, there is shown one venting means that could beused to advantage.

This venting means includes a small diameter tubular member 108, havingan outer end sealably engaged in an opening formed in the side wall ofthe reservoir. Preferably, themember 1081s disposed as close to themidlength point of the reservoir as possible, although as shownit-can beto one or the other side of the mid-length point to a slight extent.

In any event, the member 108 is either press-fitted or otherwise fixedlyengaged in the opening formed in the reservoir wall. Member 108 extendsradially inwardly of the reservoir, having an open inner end acrosswhich extends a stop pin 110, against which seats a ball. element 112freely rotatable within the member 108 and having a diametricallyextending slot 114. The provision ofthe slot causes the ball element tobe overbalanced to one side of its center, as a result of which the ballelement will at all times tend to gravitate to a position such as shownin Figure 7, that is, a position in which its solid portion is at thelower side'and the slotted portion at the upper side of the ballelement.

A plug 116 is threaded, with the member 108 being correspondinglythreaded. Plug 116 is engaged in the outer end of the member 108, and isformed with an axial, small-diameter extension 118. A bore 120 extendsfully from the outer end of the plug to the inner end of the extension,communicating with the slot 114. Slot 114 is in turn in communicationwith the interior of the member 108, and, of course, the member 108communicates with the interior of the reservoir.

. The ball element has a loose fit within the member 108, so that aircan pass the ball element and flow through core 120.

By. reason of this arrangement, during normal use of the device, thefluid level would be such as to be below the mid-length point of thecylinder, that is, the cylinder would be normally less than half full offluid. Therefore, the fluid will not surround the member 108, so thatduring the pumping action air can flow freely through bore 120 into thereservoir to prevent the formation of a partial vacuum.

Subsequently, when fluid is returned to the reservoir from the chamber106, it will displace air within the reservoir, said air flowingoutwardly through the bore 120 to permit the inflow of fluid.

It is believed apparent that the invention is not necessarily confinedto the specific use or uses thereof described above, since it may beutilized for any purpose to which it may be suited. Nor is the inventionto be necessarily limited to the specific construction illustrated anddescribed, since such construction is only intended to be illustrativeof the principles, it being considered that the invention comprehendsany minor changes in construction that may be permitted within the scopeof the appended claims.

What is claimed is:

1. In a hydraulic tool of the class described, a body including a fixedjaw; a movable jaw mounted on the body for movement toward and away fromthe fixed jaw; and an operating mechanism for the movable jaw includinga support rod engaged in the body and a hydraulic cylinder eccentricallydisposed in respect to the rod and mounted thereon for rotation to aplurality of positions in respect to the body, the eccentric dispositionof the cylinder in respect to the rod ofisetting the center of gravityof the cylinder from the rod, whereby the cylinder will move to each ofsaid positions by gravitational action.

2. In a hydraulic tool of the class described, the improvement of claim1, and said hydraulic cylinder extending longitudinally of the body.

3. In a hydraulic tool of the class described, the improvement of claim2, wherein the cylinder rotates on an axis eccentric to the cylinder.

, 4. In a hydraulic tool of the class described, the improvement ofclaim 3, and said body including a handle having a longitudinal openingwithin which said cylinder is disposed, said axis extendinglongitudinally and centrally of the opening in the general plane of thehandle,

5. In a hydraulic tool of the class described, a body and an operatingmechanism for the movable jaw including a cylinder having a reservoirfor hydraulic fluid, said mechanism further including a support rodcarrying the cylinder and engaged in the body, said rod having a borecommunicating with the reservoir, pump means working in said bore andadapted to pump fluid thereinto, and means extending between the supportrod and said movable jaw adapted for shifting the movable jaw responsiveto the pumping of fluid into the bore.

6. In a hydraulic tool of the class described, the improvement of claim5, said operating mechanism further including a flexible tube connectedat one end to the support rod in communication with the bore and havingits other end opening into the reservoir to provide said communicationbetween the bore and reservoir, and a weight on said other end of thetube, for movement of said other end of the tube toward the lowermostportion of the cylinder in each position to which the tool is shifted bya user.

7. In a hydraulic tool of the class described, the improvement as inclaim 6, said support rod extending longitudinally of the cylinder ineccentric relation thereto, the support rod being freely rotatable inthe body and being rigid with the cylinder, for rotational movement ofthe cylinder by gravitational action to a plurality of positions inrespect to the body, said flexible tube being freely movable, at saidother end thereof, toward the lowermost portion of the cylinder in eachposition to which the cylinder gravitates.

8." In' a hydraulic tool of the class described, the improvement as inclaim 7, wherein the pump means includes inlet and outlet check valvescontrolling flow of fluid through the bore, a pump rod slidable in thebore and adapted for drawing fluid into the bore responsive to slidablemovement of the pump rod, a handle disposed exteriorly of the body andengaged with the pump rod, for moving the same under the control of auser, and a normally closed valve operable by a user to permit re turnflow from the bore to the reservoir.

9. In a hydraulic tool of the class described, the improvement of claim8, wherein said means extending between the support rod and movable jawincludes a ram extendible from and slidably mounted within the supportrod, said ram being adapted for extension from the support rodresponsive to the pumping of fluid into the bore, and a bell crankpivotally mounted upon the bodyand engaged at its opposite ends with theram and movable jaw respectively.

References Cited in the file of this paten UNITED STATES PATENTS 491,222Pellet Feb. 7, 1893 566,176 Hunt et a1. Aug. 18, 1896 1,271,365 ReynoldsJuly 2, 1918 2,517,941 Stubbs Aug. 8, 1950 2,708,383 Herbst et al.May'17, 1955 2,814,872 Gerrans Dec. 3,1957 2,816,468 Lawrenow Dec. 17,1957 2,871,743 Kelley Feb. 3, 1959 "xiv mmy.

